boiler?

I have a vaillant boiler ecotec pro 28 ( it is new, 1 year only, installed last year by britih gas ). The dial in the pressure gauge crossed the grey area and nealy touched the red area. I was worried and switched off the boiler. It was on timer.It has now returned to normal ( half-way in the grey area). I amd worried the same thing may happen tomorrow when it is on timer.
Please advice course of action !